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August 2, 2005
Have You Ever Seen Inside a Model T's Engine?
Last week, I had the opportunity to sit in with a small class of students tearing down a Model T engine—not in a vo-tech school, but in an Ivy League University.
These students aren't lightweights, by any means, and are all on a mechanical engineering and aerospace track. One, for example—a licensed pilot—is designing a craft to be flown to Mars. Two others, together, are building a gas turbine for their thesis. Yet, there they were, disassembling a Model T engine—to learn.
I've seen a lot of engines apart, and have even fixed and built a few of my own. (Yes, they actually ran and ran well. I miss that, actually.) There was something beyond the students, the spotless machine shop, and the thick enthusiasm in the air tool-noisy shop: that engine. My God, what a huge chunk of metal, what with the engine block and transmission case integrated as a single casting. For all that metal, on the outside, it struck me that there wasn't much on the inside. I had to keep ratcheting myself back from that which today is commonplace, to what is was like in days of the T.
I mean, c'mon. Little itty-bitty connecting rod journals (shown at left) riding on bearings that weren't even babitted until the later years of that model's existence. Splash lubrication. Gravity-fed fuel. The crankshaft was laughable (shown in-block above), with only three main bearings and no counterweighting. Again, I had to pull myself back to reality. This wasn't about high-rpm operation; it was about design, packaging, and manufacturing efficiencies. In this particular example, it was also looking 1921 right in the face. So, that which was at first laughable, even repulsive, became elegant. That engineers and a manufacturer could make that work at all, let alone with a reasonable level of reliability for its day, was truly a triumph.
Twenty horsepower. Maximum. That's all she wrote. Torque numbers don't seem easy to come by, though the expert on-hand said that it produced 60 ft. lbs. of torque, most of which was available shortly off-idle and held on with a very flat curve up to its maximum of 2,000 rpm. Push it much past that and, apparently, the engine would shake itself to pieces—with no counterweights (until later models), this makes sense. Undersquare bore and stroke make more torque than oversquare designs. But three times the amount of torque than horsepower? I can see this in a diesel, but in a 4-stroke cycle engine? I don't get it. Could someone jump in and explain, please?
Yeah, we all know that is was the world's first mass-produced automobile, on the world's first moving production line. We all know about Henry Ford making floorboards from shipping crates. We all know that this was in the era of the horse and buggy. But, try to put this in perspective: the Model T Runabout—the whole freakin' car—was advertised at $260 in 1925 according to this source. (The picture at this link, however, indicates a file name for a '26. Oh, well. What's a year between friends.)
We all know about the manufacturing efficiencies. But 260 bucks? That completely baffles me. (Today, the set of subframe connectors alone that I want are $400.)
According to the Minneapolis Federal Reserve site, $260 in 1925 translates to $2,891.20 today. That's using the Consumer Price Index, which, according to other sites, may not be the best conversion approach. If the CPI basis is correct, then how did he do it? Let's say the CPI basis is wrong and, just for yucks, double and round-off that conversion to $6,000. Could any U.S. manufacturer today even come close to mass-producing a Model T for, say, $6,000? It certainly couldn't be done with today's safety and emissions rules in place. So, hypothetically—car-for car, same regs as then (none)—could it be done?
Think it could be done in China?
Comments?
Misc. References
Basic Model T Specs
http://www.conceptcarz.com/vehicle/default.aspx?carID=1680&optionID=0
Interesting Model T Link from Our Friends Up North – FAQs
http://www.modelt.ca/faq-fs.html
Interesting Model T Link from Our Friends Up North – Specs
http://www.modelt.ca/specifications-fs.html
Model T Camshaft/Horsepower Testing – Simulation 1
http://clubs.hemmings.com/clubsites/mtfctulsa/MTFCTulsa/Cams/simulation01.htm
Model T Camshaft/Horsepower Testing – Simulation 2
http://clubs.hemmings.com/clubsites/MTFCTulsa/cams/simulation02.htm
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Comment
3 Commentsnice piston
December 15, 2007 5:53 AMYou ask 2 questions in your article above.
1) Why 3 times more torgue than HP? You might be forgetting that there were no highways back then and most driving was still done on dirt...er, scracth that....MUD and MUCK roads. You needed lots of torque to get that gas buggy going from a standstill with 4 heavy bodies inside and lots of mud caked all over the spoke wheels.
2)Other question, could a car be produced today for the same cheap price in today's dollars? Yes, there are many models in the sub $6,000 price range worldwide. Mostly in China and India. Tata Motors in India just announced a new $2,500 car...yep, has 4 wheels, modern car body and even comes with AC.
To answer your questions;
1. 3 times as much torque as horsepower is more than believable. Remember, horsepower is a measure of power, which is work per unit *time*. The model T had such a low horsepower rating because it only ran up to 2000RPM. It had a respectable amount of torque (or work), but it did that work too slowly, thus the low horsepower.
Just as an example; if the model T engine could manage 5000RPM at 60 lbft of torque, it would produce 57 horsepower.
(Torque x Engine speed) / 5,252 = Horsepower
Going the other way (20 horsepower at 2000RPM) gives me 53 lbft of torque. Of course as you said, it's maximum torque would have happened earlier than 2000RPM, so 60 is probably fairly accurate.
Looking at the equation, it's easier to increase horsepower by raising engine RPM than it is by raising torque.
2. I'm sure it's possible to build a car for that amount of money today. Remember, modern cars are required to have airbags, seatbelts and all kinds of other safety features. They also need to meet emissions and fuel efficiency goals, so we are talking fuel injection, catalytic converters etc.
Also to be a success in the market, all cars need a decent HVAC system, a CD/radio/MP3 unit and hundreds of other things that the Model T lacked.
If a manufacturer could build a very, very basic car (like the model T), I imagine it could be even *cheaper* than the model T was.
